Analogical transfer is an essential component of cognitive processing that expands the ability of humans to solve problems in a variety of contexts. It is a powerful basis by which unique and creative solutions to problem situations are derived and serves as a common hallmark of adaptive, intellectually competent behavior in academic, work, and social environments. However, the occurrence of analogical transfer is a complex phenomena requiring the integration of a wide range of mental processes and structures. The development of many of these factors have not been extensively investigated. Interpretations of learning and transfer in younger children often emphasize the shared perceptual or surface characteristics ("identical elements") of problem situations, whereas rule-like and more abstract solution principles are more likely to be associated with explanations of learning and transfer in older children and adults. In this research a series of experiments with elementary school age children is designed to explore how similarity in perceptual surface features (main character, goal object, thematic and contextual information, mode of presenting the problem, etc.) and structural features of problems (the higher order causal solution principle) influence representation of information and transfer in analogical problem solving. This research is proposed to yield a more complete picture of whether there are developmental differences in the importance and kinds of surface features that bear upon children's noticing of analogical problem situations and how different forms of perceptual and contextual similarity affects representation of solution principles and transfer. Additionally, work is proposed to examine how structural aspects of analogical problems affect the ability of children of different ages to map analogical solution principles to transfer problems.